GAS OR OIL FIRED HEAT EXCHANGER FOR FORCED AIR HEATING UNIT

摘要

A heat exchanger is shown having an elongated combustion chamber with a burner opening in one end thereof and a pair of ducts leading from the other end to a pair of separate headers. Two groups of tubes extend from the two headers along the combustion chamber for connection with a common header, and a third group of tubes extend back from the common header to a combustion gas discharge header positioned between the first two headers, but separate therefrom.